This invention relates to infinitely adjustable cantilever support systems and, in particular, to such systems utilized for article support, e.g. shelf support.
In typical prior art cantilever support systems, it is of primary importance that the system have structural strength and also that its support component be safe from accidental slippage or disengagement from the system's other components.
It is also very desirable that said support systems be adjustable in the most efficient ways possible and without abrading or marring the system's visible surfaces. Previous systems offered for sale and/or described in patents and other publications have attempted to fulfill these requirements and have been and are inadequate.
A common type of prior art adjustable support system consists of an apertued vertical support member to which a horizontal support member is attached by means of hook-line protrusions on the bracket. These systems, such as the one described in U.S. Pat. No. 3,703,727, Engel et al, are limited in that they may be adjusted by incremental distances only and are also very often diffucult to engage or disengage.
To incorporate the advantage of being infinitely adjustable, cantilevered structural support systems have been developed which employ the use of well known principles, involving cantilevering forces, to generate sufficient friction to balance downwared forces created by article loaded horizontal support bracket. This friction, created by the horizontal support being rotated downwared under load, will, henceforth for simplicity's sake, be termed the primary frictional force.
In the design of such cantilevered support systems, it has also been found necessary to be able to generate a separate and lesser frictional force to overcome loads on the horizontal support bracket that, due to the distribution of said loads, does not have adequate leverage to create enough primary frictional force to overcome the reducing factor created by the co-efficient of friction of the materials used in the spports. Reliance on such expedients as a load placed very close to the connection point of the structural support components or the dead weight of the horizontal bracket is displaced in that such loads require a secondary frictional force to be generated in order to prevent slippage and/or disengagement of the structural system's components.
Examples of such cantilevered structural support systems are those described in U.S. Pat. No. 4,098,482 to Hamblin and U.S. Pat. No. 3,865,337 to Towfigh, et al. These systems incorporate a horizontal support member that is rotated downward to interlock with the vertical support and to generate the necessary frictional forces. This is done at the cost of safety, as any accidental upwardly directed force on the support bracket will cause it to slip in its vertical support member. Another deficiency to be found is that, in order to engage or remove the horizontal support brackets, those brackets already in place must be moved or removed. Should the vertical support members be verylong, it is very awkward to engage or remove the horizontal brackets.
Support systems such as the design-type described in U.S. Pat. No. 3,848,844 to Barnet use a locking mechanism, such as a cam or a bolt, to generate adequate secondary frictional forces. The disadvantage inherent in this design-type is that, in manipulating the locking mechanism, it is necessary to use a tool, such as a wrench, and that in manipulating said mechanism, the visible surfaces of the system are indented or marred. It can also be seen that these systems retain the same problems aforementioned regarding quick and easy removal of the horizontal brackets.
Another class of article support system, exemplified in disclosures such as U.S. Pat. No. 3,664,627 to Sykes and U.S. Pat. No. 4,223,863 to Berman, includes systems designed so that the horizontal support brackets may be engaged without having to slide the brackets into the end of the vertical support as in the above classes. However, due to the fact that the brackets still must be rotated for adjustment, any brackets in place above their arc of rotation must be moved. Also, again, the problem of accidental disengagement results in an unsafe support system.
There are structural support systems, such as U.S. Pat. No. 3,203,375 to Shroeder, that are designed so the horizontal support may be directly engaged into the vertical supporting member without the need to rotate the bracket. It can be seen, though, that in order to generate adequate secondary frictional forces excessive hand pressure is required to manipulate the bracket. As stated before, in citing other patents, accidental disengagement is a hazardous factor of the design.
Many systems, some of which have been previously mentioned, generate required secondary frictional forces by the rotational manipulation of the horizontal support bracket. This type of engagement also has the effect of compounding stress on the connecting joint of the structural components and of unduly indenting or marring the track. Therefore, systems using such engagement types must rely more on the frictional forces generated by the primary frictional force and to accomplish this the depth of the horizontal brackets connecting base is kept relatively shallow. However, by decreasing the depth of base, greater stress is placed on the connecting joint of the structural components. This problem is especially acute in these structural support systems aforementioned where horizontal brackets use only a single protuberance at their connecting base to engage the vertical structural support. To compensate for this deficiency either thicker or stronger materials must be incorporated in the structure, resulting in a bulkier support system of greater cost than necessary.
It is, therefore, an object of this invention to provide an infinitely adjustable structural support system which provides a structurally strong and frictionally tight joint between structural components while enabling easy and rapid assembly of said components.
It is a further object of this invention to provide a strong and infinitely adjustable support system whose main components cannot be accidentally disengaged.
It is a further object of this invention to provide an infinitely adjustable support system whose integral components do not mar or blemish the visible surfaces of said system.
It is a further object of this invention to provide an infinitely adjustable support system having the aforementioned advantages, using the minimum of materials and using the simplest and most efficient manufacturing techniques.